The invention relates to an epitaxial growth reactor for processing at least one semiconductor wafer by exposing it to a reactive gas flow the wafer being heated and giving off heat.
The walls of epitaxial growth reactors tend to become soiled by deposits produced by a reaction between the reactive products used.
In the case in which the wafers are in a horizontal position, the problem of deposits is particularly serious, since these deposits have a tendency to flake under the influence of differences in the coefficients of expansion and to cause fragments to fall on the wafers. Each fragment results in defects in one of the plurality of circuits under construction (each wafer is subdivided in a large number of circuits).
Soiling of the walls of the epitaxial growth reactors, which is particularly annoying near the useful surfaces of the wafers can be prevented by raising the walls to a predetermined temperature.
A means to achieve this is to provide a temperature control of the walls. This is taught by the document JP.A. 60 262418. The reactor described in this document includes a helical pipe applied on the reactor wall and in which a fluid is circulated. The temperature of the wall is controlled in that the temperature is measured and, by feedback, acts on a valve regulating the flow rate of the fluid. However, such a means is complicated and expensive.